scholarly journals What can be inferred from moiré patterns? A case study of trimesic acid monolayers on graphite

2017 ◽  
Vol 204 ◽  
pp. 331-348 ◽  
Author(s):  
Saskia Spitzer ◽  
Oliver Helmle ◽  
Oliver Ochs ◽  
Joshua Horsley ◽  
Natalia Martsinovich ◽  
...  
Keyword(s):  
Self Assembly ◽  
Lattice Parameter ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Trimesic Acid ◽  
Moire Pattern ◽  
Porous Networks ◽  
Moiré Pattern ◽  
Moire Patterns ◽  
Moiré Patterns

Self-assembly of benzene-1,3,5-tricarboxylic acid (trimesic acid – TMA) monolayers at the alkanoic acid–graphite interface is revisited. Even though this archetypal model system for hydrogen bonded porous networks is particularly well studied, the analysis of routinely observed superperiodic contrast modulations known as moiré patterns lags significantly behind. Fundamental questions remain unanswered such as, are moiré periodicity and orientation always the same, i.e. is exclusively only one specific moiré pattern observed? What are the geometric relationships (superstructure matrices) between moiré, TMA, and graphite lattices? What affects the moiré pattern formation? Is there any influence from solvent, concentration, or thermal treatment? These basic questions are addressed via scanning tunneling microscopy experiments at the liquid–solid interface, revealing a variety of different moiré patterns. Interestingly, TMA and graphite lattices were always found to be ∼5° rotated with respect to each other. Consequently, the observed variation in the moiré patterns is attributed to minute deviations (<2°) from this preferred orientation. Quantitative analysis of moiré periods and orientations facilitates the determination of the TMA lattice parameter with picometer precision.

Anomalous moiré pattern of graphene investigated by scanning tunneling microscopy: Evidence of graphene growth on oxidized Cu(111)

Nano Research ◽  
2013 ◽  
Vol 7 (1) ◽  
pp. 154-162 ◽  
Author(s):  
Nicolas Reckinger ◽  
Eloise Van Hooijdonk ◽  
Frédéric Joucken ◽  
Anastasia V. Tyurnina ◽  
Stéphane Lucas ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Graphene Growth ◽  
Moire Pattern ◽  
Moiré Pattern

INTERCALATION OF COBALT UNDERNEATH A MONOLAYER OF GRAPHENE ON Ru(0001)

2012 ◽  
Vol 19 (04) ◽  
pp. 1250041 ◽  
Author(s):  
Q. LIAO ◽  
H. J. ZHANG ◽  
K. WU ◽  
H. Y. LI ◽  
S. N. BAO ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Graphene Layer ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Moire Pattern ◽  
Moiré Pattern

Scanning tunneling microscopy is used to study intercalation of cobalt underneath a graphene layer on Ru(0001) . Deposition of cobalt on graphene/ Ru(0001) at 873 K leads to the intercalation of cobalt between the graphene layer and the Ru(0001) substrate, and the intercalation is associated with Co diffusion at steps and defects. The morphology of graphene/ Co/Ru(0001) shows moiré pattern, as same as that of graphene/ Ru(0001) . The bright areas where Co islands exist are hcp regions of graphene/ Ru(0001) . The intercalated Co islands have a pseudomorphic structure superimposed on Ru(0001) .

A Case of Quasi-Infinite Visual Acuity and Illusory Size

Perception ◽  
10.1068/p6398 ◽  
2009 ◽  
Vol 38 (5) ◽  
pp. 781-783
Author(s):  
Wolf M Harmening
Keyword(s):  
Visual Acuity ◽  
Real Life ◽  
Apparent Size ◽  
Traffic Signs ◽  
Physical Size ◽  
Moire Pattern ◽  
Moiré Pattern ◽  
Moire Patterns ◽  
Size Discrepancy ◽  
Moiré Patterns

In certain real-life situations, moiré patterns can enhance the observer's ability to resolve fine spatial detail of solid structures, theoretically to unlimited degrees. An example of such a situation can be seen in traffic signs on the M25 motorway around London. Moreover, owing to the interferential nature of the moiré pattern, its angular physical size is independent of observer distance, and thus creates an apparent size discrepancy: the closer you get, the smaller the size of the pattern appears to be—an illusory situation resembling Michael Ende's tale of the pseudo-giant Mr Tur Tur.

scholarly journals Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

2020 ◽  
Vol 11 ◽  
pp. 1470-1483
Author(s):  
Domenik M Zimmermann ◽  
Knud Seufert ◽  
Luka Ðorđević ◽  
Tobias Hoh ◽  
Sushobhan Joshi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Photophysical Properties ◽  
Scanning Tunneling ◽  
Supramolecular Organization ◽  
Tunneling Microscopy ◽  
Porous Networks ◽  
Pyrene Derivatives ◽  
High Fluorescence

The controlled modification of electronic and photophysical properties of polycyclic aromatic hydrocarbons by chemical functionalization, adsorption on solid supports, and supramolecular organization is the key to optimize the application of these compounds in (opto)electronic devices. Here, we present a multimethod study comprehensively characterizing a family of pyridin-4-ylethynyl-functionalized pyrene derivatives in different environments. UV–vis measurements in toluene solutions revealed absorption at wavelengths consistent with density functional theory (DFT) calculations, while emission experiments showed a high fluorescence quantum yield. Scanning tunneling microscopy (STM) and spectroscopy (STS) measurements of the pyrene derivatives adsorbed on a Cu(111)-supported hexagonal boron nitride (hBN) decoupling layer provided access to spatially and energetically resolved molecular electronic states. We demonstrate that the pyrene electronic gap is reduced with an increasing number of substituents. Furthermore, we discuss the influence of template-induced gating and supramolecular organization on the energies of distinct molecular orbitals. The selection of the number and positioning of the pyridyl termini in tetrasubstituted, trans- and cis-like-disubstituted derivatives governed the self-assembly of the pyrenyl core on the nanostructured hBN support, affording dense-packed arrays and intricate porous networks featuring a kagome lattice.

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